Illinois Election Results

Republicans are on the defensive in several races in Illinois, one of the few Democratic bastions in the Midwest. The state has long faced budget problems and immense pension liabilities, and it has lost population in recent years.

Gov. Bruce Rauner, a Republican, was elected in 2014 with a mandate to get Illinois’s finances in order, but his tenure has been bumpy. He is perhaps the country’s most vulnerable incumbent governor seeking another term.

J.B. Pritzker, the Democratic nominee for governor, has criticized Mr. Rauner over a budget stalemate that lasted more than two years. But Mr. Pritzker has faced troubles of his own: He paid $330,000 in back taxes on a Chicago mansion after an inspector general described a “scheme to defraud.”

Both Mr. Rauner and Mr. Pritzker are wealthy businessmen, and both have poured tens of millions of dollars of their own money into their campaigns. The race has been one of the most expensive in the country.

Representative Peter Roskam, a Republican, is trying to hold on to his seat in an affluent district west of Chicago that Hillary Clinton carried in 2016. His Democratic opponent, Sean Casten, a businessman, has focused his campaign on health care and has called for stricter gun control laws. Mr. Roskam’s district is one of several suburban areas across the country where Republican incumbents are vulnerable because of some voters’ distaste for President Trump.

Democrats are seeking to unseat Representative Mike Bost in a Southern Illinois district that supported former President Barack Obama in 2012 but swung heavily to President Trump in 2016. The district includes suburbs east of St. Louis, as well as farmland and coal mining towns to the south. Mr. Trump claimed credit for the reopening of a steel plant in Granite City, Ill., after imposing tariffs on imported steel.

Representative Rodney Davis, a three-term Republican, is seeking re-election in a vast district that stretches from the suburbs east of St. Louis through farmland and into the college towns of Champaign and Normal.

Mr. Davis carried the district by nearly 20 points in 2016, but Democrats are optimistic about the chances of Betsy Londrigan, a fund-raiser who once worked for Senator Dick Durbin. Ms. Londrigan has focused her campaign on health care.

Lauren Underwood, a nurse who worked in President Barack Obama’s administration, sees an opening to flip a suburban and exurban district that has long supported Republicans. The incumbent, Representative Randy Hultgren, won by 19 points in 2016 and has a conservative voting record. Ms. Underwood, a self-identified progressive who grew up in suburban Chicago, has emphasized health care on the campaign trail. Mr. Hultgren’s seat is one of several that national Republicans are worried about losing because of President Trump’s lack of popularity in well-educated suburbs.